The custom made bands are top notch...well worth the price.
There are replacement bands made for the larger barreled 2028's made of metal...but those barrels are 1mm larger in diameter, so while they fit the gas tube of a 78, the barrel is too small. The metal bands for the 2078 wil also use a full diameter screw...the 78's screw is thinned in the middle....so you'll have to oepn the recess in the barrel a little. Can bush the upper section to a nice slide fit (and 3 spaced teflon strips works fine for that). Not a perfect solution, but a cheap one.
Another imperfect (but even cheaper) soluttion is one I'm still using (and being hard-headed, will keep on using until something breaks loose). Will epoxy the issue band to the gas tube, but not the barrel. Doesn't really add any to the ultimate strength, but does tend to stabalize things. Doesn't harm dissassebly, the barrel can still slide out once the screw is removed, the band just stays on the gas tube.